When I asked my older sister, who is a locally famous slut, to let me have sex with her, she instantly refused and said, ``It's absolutely impossible.'' She couldn't give up, so she negotiated with him, saying, ``You can keep your panties on, so let me bare your legs.'' Her older sister felt sorry for her and reluctantly agreed! I was overjoyed and rubbed my dick against my girlfriend's sister's panties, and of course it felt better than masturbation, so I ejaculated a lot! When I thought, ``I'm so angry,'' I looked at the semen and turned into a slut.